1. Field of the Invention
The present invention relates to a semiconductor device, in which an electrical connection between electrodes on a semiconductor chip and inner leads of a lead frame is provided and an electrical connection between outer leads of the lead frame and wiring patterns on a print circuit board is provided, and its manufacturing method, and more particularly to a semiconductor device wherein the distance between electrodes on the semiconductor chip to provide the electrical connection and the distance between the inner leads of the lead frame and the distance between the outer leads thereof are small, and its manufacturing method.
2. Description of the Related Art
When the semiconductor device is manufactured, there are numerous portions where an electrical connection is to be provided such as a portion between an electrical pad on a semiconductor chip and an inner lead of a lead frame, and a portion between an outer lead of the lead frame and a wiring pattern on a print circuit board.
Conventionally, for example, the electrical connection between the electrode pad on the semiconductor chip and the inner lead is made by a metal bonding such as a wire bonding using AU wire or Al wire, a TAB (Tape Automated Bonding) method, an ohmic contact such as a metal contact between a bump electrode on a flip chip and a lead, and the like.
Regarding the connection by the wiring bonding, the shortest distance between adjacent wires is restricted by the outer shape of a bonding capillary to be used. Due to this, it is difficult to reduce the distance between the pads on the semiconductor chip to be about 100 .mu.m.
Moreover, in order to connect an Au ball or an Al wire to an aluminum pad on the semiconductor chip, it is necessary to apply a physical load such as by heating, pressing, or ultrasonic vibration. Therefore, damage is often applied to the semiconductor chip itself under the electrode pad.
In a case where TAB system or the flip chip is used, it is necessary to metal-connect an Au bump or an plating bump to the inner lead. Due to this, the temperature often increases higher than that of the wire bonding connection, so that physical damage due to pressure occurs. In this case, the distance between the pads can be reduced to about 80 .mu.m, however, there is a limitation in the reduction of the bump size because of the use of the metal connection. Moreover, a large number of portions are connected at the same time. Due to this, as the number of portions to be connected is increased, it is more difficult to obtain a stable connection in view of the height of the bump, and the condition of the connection. Due to this, it is required that the process conditions be stabilized.
The above-mentioned problem occurs in not only the electrical connection between the pad on the semiconductor chip and in the bump and the inner lead but also in the electrical connection between the outer lead and the wiring pattern on the printed circuit board.